1. Field of the Invention
This invention pertains to a fitment for a spouted pouch, particularly one with a canoe-type base or meltable fin wherein the plastic is reduced in transition areas and in the wall thickness of the base. To accelerate and maintain the integrity of the process for installing a fitment, a heated mandrel shaped and sized to the inner diameter of the fitment passageway is used.
2. Description of the Prior Art
In the prior art, it is known to use a fitment/spout with a canoe shaped base with extended meltable fins oriented 180xc2x0 apart, and multiple horizontal ribs spaced evenly across the height of the canoe. The canoe shape and the meltable fins assure gradual transition from the two plies of film (one on each side of the fitment) to the maximum width of the canoe in the diametrical center of the fitment.
In order to seal or weld the fitments to the film at the fastest possible rate, and to reduce potential leaking at the base, the base can be made with horizontal.ribs to increase the sealing pressure and to reduce the dwell time. However, the sealing pressure must not damage or misshape the inner diameter of the fitment. To avoid such problems, the canoe base is typically made more massive than would otherwise be required.
Because the maximum temperature of the jaws is limited by the characteristics of the film, the two driving variables of the sealing equation become the dwell time and the pressure. That is, a canoe base which is enlarged for the above reasons requires increased dwell time and pressure to bring it to the sealing temperature, which is counterproductive to the production rates of the fitment attachment process.
The attachment of this kind of fitment is disclosed in U.S. patent application Ser. No. 09/452,714 entitled xe2x80x9cMethod for Attaching Fitment at Longitudinal Fin Seal and Package Resulting Therefromxe2x80x9d filed on Dec. 2, 1999.
Other prior art includes U.S. Pat. No. 5,911,340 entitled xe2x80x9cSpout Assembly, Spout Assembly Manufacturing Apparatus and Package with Spout Asssemblyxe2x80x9d issued on Jun. 15, 1999 to Uematsu; U.S. Pat. No. 5,716,471 entitled xe2x80x9cMethod for Securing Articles to Laminatesxe2x80x9d issued on Feb. 10, 1998 to Pape; U.S. Pat. No. 4,909,434 entitled xe2x80x9cMoisture Impervious Carton Having One-Piece Pouring Spout Sealed to Innermost and Outermost Surfacesxe2x80x9d issued on Mar. 20, 1990 to Jones et al.; and U.S. Pat. No. 3,894,381 entitled xe2x80x9cMethod and Means for Attaching Fitments to a Bag or Pouch on a Packaging Machinexe2x80x9d issued on Jul. 15, 1975 to Christine et al.
It is therefore an object of the present invention to provide a fitment with canoe-shaped walls which can be installed between two plies of plastic film with reduced dwell time and/or reduced jaw pressure.
It is therefore a further object of the present invention to provide a fitment with canoe-shaped walls which can be installed at high speeds.
It is therefore a still further object of the present invention to provide a fitment with canoe-shaped walls which can reliably maintain its shape during installation.
These and other objects are attained by providing an injection molded fitment with reduced-plastic in the canoe base, to retain the shape and length of the canoe, but to reduce the amount of plastic in transition areas and in the wall thickness of the base. This reduces the mass of the canoe and the required preheat/sealing dwell time. An alternative embodiment employs radially extending meltable fins in place of the canoe base. In order to compensate for the reduction in the rigidity of the base and the resulting reduction in ability to withstand the pressure of the sealing bars, the fitment is installed with a heated mandrel inserted through the inner diameter of the fitment. More specifically, as the fitment travels along the track from the vibratory bowl to the sealing station, a heated mandrel shaped and sized to the inner diameter of the fitment is inserted into the inner diameter of the fitment. In order to avoid unnecessary softening of the fitment, the temperature of the mandrel is typically 20-30xc2x0 F. below the softening temperature of the resin from which the fitment is molded. In order to heat the fitment thoroughly from the inside prior to installation without slowing down the installation process, the mandrel is typically inserted at least one cycle away from the sealing position. The insertion of the heated mandrel into the inside diameter of the fitment will further prevent the collapse or misshaping of the base. Indeed, the sealing dwell time is thereby reduced by both the reduction of plastic in the base and the heating of the fitment by the mandrel.